Date: Thu, 26 Mar 2009 16:22:36 +0200 From: Andriy Gapon <avg@icyb.net.ua> To: Erik Trulsson <ertr1013@student.uu.se> Cc: Ronald Klop <ronald-freebsd8@www.klop.ws>, freebsd-stable@freebsd.org Subject: Re: remote debug over usb vs. old serial cable? Message-ID: <49CB8FAC.4080505@icyb.net.ua> In-Reply-To: <20090326130634.GA36270@owl.midgard.homeip.net> References: <op.uregvzva8527sy@82-170-177-25.ip.telfort.nl> <20090326130634.GA36270@owl.midgard.homeip.net>
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on 26/03/2009 15:06 Erik Trulsson said the following: > On Thu, Mar 26, 2009 at 01:56:13PM +0100, Ronald Klop wrote: >> Hello, >> >> In the past I could catch a panic during boot via a serial cable connected >> to another computer. >> My new computer only has USB-ports and ethernet. What kind of cable do I >> need now to do remote debugging? >> The old computer also has usb, so I think the connection should be in that >> corner. >> They all run 7-STABLE. > > USB won't work for that purpose. It requires far too much kernel support to > be useful after a panic. Erik, in fact, there is a special USB (EHCI) mode for such purposes: http://www.coreboot.org/EHCI_Debug_Port But that requires some special HW in addition to SW support which our doesn't have. BTW, Ronald, it is possible that you might have a serial header on motherboard which is not connected to any traditional port. -- Andriy Gapon
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